Buffer



Feb. z 1926.

E. J. EMERY BUFFER Filed Dec. s, 1921 Patented Feb. 2, '1926.

i UNITED` STATES ELIAS J. EMERY, OF LYNN, MASSACHUSETTS.

BUFFER.

Application inea December s, 1921. serial No. 520,888.

To all whom t may concern.'

- Be it known that I, ELIAS J. EMERY, a citizen of the United States of America, and resident of Lynn, in the county of Essex and State of Massachusetts, have invented` new and useful Improvements in Buffers, of which the followlng is a specification.

This invention relates to resilient buffers.

Devices for preventing or lessening the shock of.collision of parts ofmachinery have heretofore been provided in vmany sitnations, and generally consist of means adapted to interpose a yielding and noiseless buffer between the metal parts brought together during operation. Familiar devices for this urpose are dash-pot pistons, blocks .of raw-hide or vulcanized rubber, and pads of leather or felt. The useful life of such structures is undesirably short, and a principal object of this invention is to provide a reliable device for such uses, which shall have a relatively long life, and which shall have an improved function in bringing to rest the moving part.

Particularly, the present invention is con.- cerned with providing a buffer which will begin its action at first contact by deformation under slight pressure, and thereafterI continue its action by deformation requiring more and more pressure, until the moving part is brought to rest.

In order to accomplish these purposes, the invention provides a resilient plug, preferably ofrubber or a rubber substitute, so designed as to utilize the tensile resilience of a portion of the material of the device in the first instance, and thereafter to utilize the resilience of compression of the material. A subordinate object of the invention is to so design the device as to cause all of the resilient material employed to participate in the padding or resillent protection between the parts.

While there are many uses for the device, I shall, by wa, of example, describe it in connection wit the su porting springs of an automobile, in whic it finds a typical use.`

In the drawings,

Figure 1 is a front elevation of the running gear of an automobile showing the improved bufi'er attached to the front spring;

vFigure 2 Section on the line 2-2, Fig-1;

Figure 3 is an enlarged section of the buffer under compression;

Figure 4 is an enlarged section showing a modification; and

Figure 5 is a side elevation of the front of an automobile showing the buffer used with a different type of spring suspension.

The improved buffer comprises a body 6 moulded from rubber, rubber substitute or rubber compound vulcanized or otherwise solidified to an elastic, tough resilient state.

and body 6, including bridge 8, are placed under tensile strain, since the stress under which integral bridge 8l will stretch to yield is less than the strain required substantially to deform and compress plug 7 or body 6. If the pressure is continued and increases. the plug 7 and its supporting body 6 are then subjected to compressive stress. I lprefer to arrange for the compressive resilience of the plug to become effective gradually by so forming its inner end as to increase its compressive resilience proportionally to the inward displacement of the movable body. This is effected by pointing, sloping or doming the inner portlon of the plug, so as to provide a rounded, frustro-p amidal, frustro-'conical or conical portion or example, as shown at 11) adapted to bring an increased area of the body to rest against its seat as it is forced further inward. It will p be noted that since, as shown in Fig. 2, the extremity of the portion 11 is normally spaced by a certain distance. from the plane of the base of the buffer, the plug has a certain limited path of free movement before it engages the member 12.

Recess 10 is closed `by a supportin plate 12 upon which the buffer is mounte One means for retaining the buffer in position comprises an under-cut flan e 13 on plate 12 receiving the inner end 'of ody 6. While the under-cut of the flange, combined `with the resiliency of body 6 will be sulicient to retain the butler in place, body 6 may, if desired, be cemented or otherwlse fastened Vin the cup-shaped opening provided therefor by flange 13. Plate 12 may be of any desired shape which will fit it for use 1 n the particular place to which the buffer 1s to be applied. In Figs. 1 and 2 the butler is shown applied to the front spring of a popular type of automobile. In this` case plate 12 takes the place of the retaining may be recessed, if desired, to receive thereover the U-bolts E.

In order to prevent the inner. edge of flange 13 from cutting into the relatively n soft kmaterial of which body 6 is made,

which may result from the frequent expansion of body 6 under compression, the latter may have applied thereto a section of protective material 16 fitted in a recess 17 in body 6 opposite the outer end of fiange 13, as shown 1n Fig. 4. The protective ma.- terial should be iexible in order not to interfere unduly with the action of the buffer under compression, and may comprise textile material in various forms such as heavy ta e.

lr)Ihe action of the buffer under compression is illustrated in Fig.. 3 lin which the direction of thrust is indicated by arrow al.

y As previously described, the initial pressure upon the end of 'plu 7 forces the latter upwardly placing bri ge 8 and the adjacent portions of the buffer under stretching or tensile strain. At the same time some l compressive strain is applied to the plug itself and to the base portionof body 6. When projection 11 on thebase of plug 7 contacts with plate 12 heavy compresslve strain is set up throughout plug 7 producing gradually increasin resistance to the downward movement o the spring. The

air pocket in recess 10 likewise adds to theA resistance and to the resilience of the buffer. The structure of the buffer is such that all parts thereof are. utilized, either through tensile orcompressive stress, to resist shock as clearly illustrated in Fig. 3.

I claim: 1. Shock absorbing mechanism. compris;

ing a resilient buffer having therein an inthan t e tegra'l -ro'ecting plug of alength eater len h elsewherev of said uffer, said plug belng resillently supported for movement with respectto the remainder of the buffer, and means for supporting said bui'er on an element between which and a second element shock is to be absorbed.

2. In an apparatus of the character described, in combination, means for attaching a buffer toa machine elment, and a resilient buffer associated with said means and comprising a body molded of a plastic substance having tensile resilience and having therein a partially separated `portion constituting a plug of greater length than the length of said builer at other points, said plug being movable in a direction to cause approach of its' outer extremity to said machine element, and being connected to the body of said buffer by an integral resilient bridge.

3. A resilient buffer comprising a body adapted 'to interlit with an undercutseat in a machine element and having therein and partially separated therefrom an integral plugl of the same substance as the buffer normally projecting beyond the body of the butter, and a connecting bridge between the body of the buffer and the plug adapted t0 be stretched under pressure Aupon the plug and return the plug to its normal projectmg position upon cessation of pressure by the tensile resilience of the bridge.

4. A resilient buffer made as a round body having a base adapted to a seat in a machine element, said base having therein Aa depression partially isolating a part of the substance ofthe buffer within the margins of the depression, said buli'er having a corres o ndin'g depression in its outer surface de nlng a projecting integral plug of the .therefrom a portion of the integral substance ofthe buffer constituting a plug,said plug being held to project outwardly from the surface of said bu'er by the tensile elasticity of a portion of the substance of the .material of the buffer, and adapted thereby buffer joiningsaid plug to the buffer in combination withseating means in contact with said lnner surface and a mach-me ele- `ment to be cushioned by the buffer.

6. A resilient buffer comprising a body of plastic substance, a depression in the upper surface of said -body and a correspondlng recessin the lower surface, the twodenlng a plug normally projecting above said upper surfaceV and connecte-d to said' bodyl byan integral bridge, and a projection on4 the lower part of said plug partially filling said recessl in combination with seatin means in contact with said inner Surface an a machine element to be cushioned bythe buffer.

7. A resilient buffer comprising a conical body of plastic substance, a depression in the base surface of said body and a corresponding recess in the apex surface, the two defining a plug normally projecting above said upper surface and connected to said body by an integral bridge, and an integral projection on the lower part of said plug partially filling said recess, whereby on application of-prcssure to the plug, the latter including said projection is put under compressive strain and adjacent portions of the plug and the body including said bridge under tensile strain.

8. A resilient buffer comprisinga body of plastic substance, a depression in the upper surface of said body and a corresponding recess in the lower surface, the two defining a plug normally projecting above said upper surface and connected to said body by an integral bridge, a projection on the lower part of said plug partially filling said recess, and means receiving and supporting Said body comprising a cup-shaped member.v

9. A resilient buffer comprising a body of plastic substance, a depression in the inner surface of said body and a corresponding recess in the outer surface, the two delining a plug normally projecting beyond said outer surface and connected to said body by an integral bridge, a projection on the inner part of said plug partially filling said recess, and a member having an undercut flange for receiving and supporting the inner part of said body.

10. A resilient'buffer comprising a body molded 4of, a plastic substance having an shorter than the distance which said plug projects.

121A resilient buffer having therein an integral projecting plug free to move with respect to the remainder of the buffer, the path of free movement of said plug being less than the distance which said plug projects beyond the remainder of said buffer,

and said plug having associated therewith means for increasing the resistance to movement thereof progressively as the outer end of said plug is moved in excess of the length of said path.

13. A resilient buffer having therein an integral projecting plug free to move with aspect to the remainder of the buffer, lthe path of free movement of said plug being less than the distance which said plug projects beyond the rem-ainder'of said buffer, and said plug having associated therewith means for increasing the resistance to movement thereof progressively at an increasing rate as the outer end of said plug is moved in excess of the length of said path.

Signed by me at Boston, Massachusetts, this sixth day of December, 1921.

ELIAS J. EMERY. 

